The overall goal of this research is to develop an oral treatment for Stargardt disease, a leading cause of juvenile blindness with a prevalence of about 1 in 10,000 in the United States. Vision loss in Stargardt disease is thought to originate from excessive accumulation of vitamin A aggregates (dimers) and lipofuscin granules in the eye. ALK-001, is vitamin A specifically enriched with deuterium at a position to slow the formation of toxic vitamin A dimers in the eye. In rodent models of Stargardt disease ALK-001 resulted in a decrease in vitamin A dimers, ocular lipofuscin and in improved visual function. ALK-001 is thought to retard vitamin A dimerization and lipofuscin formation without affecting the visual cycle or normal vitamin A processing and as a consequence should not lead to visual or systemic side effects. The major hypothesis of this work is that retarding vitamin A dimerization will slow lipofuscin formation and the course of Stargardt. The goal of this grant is to perform preliminary safety evaluation and determine plasma pharmacokinetics in response to two week dosing with ALK-001 so that longer trials for efficacy can be designed and conducted. The specific aim of the grant proposal is to a complete a 2 week daily dosing, double blind, clinical trial to assess the safety and plasma-pharmacokinetics of ALK-001 in subjects with Stargardt disease.